
import base64
import re
flag=""
with open("access.log","r") as f:
    for i in f.readlines():
        if "200 215" in i.strip():
            re1=re.compile(r".+f=(.*?) HTTP.+")
            re2=re.search(re1,i.strip())[1]
            re3=base64.b64decode(re2)
            #print(re3)
            re4=re.compile(b"\)==(\d+?)\);")
            try:
                re5=re.search(re4,re3)[1].decode()
                flag+=chr(int(re5))
                print(flag)
            except:
                continue
print(flag)